Laptop battery dying? Signs and how to replace it
How to tell the battery is worn out
A laptop battery loses capacity over time — that's normal. The problem is when it starts getting in the way. These are the signs we see every day in the shop:
- It lasts far less than it used to — half an hour and it already wants the charger.
- The laptop shuts down suddenly, even showing 20% or 30%.
- It only runs plugged in; pull the cable and it dies.
- Windows shows the "Consider replacing your battery" warning.
- The battery is swollen and the keyboard or trackpad has lifted. This is dangerous — stop using the laptop.
Check battery health without opening anything
On Windows: press the Windows key, type cmd, open Command Prompt and type:
powercfg /batteryreport
It saves an HTML file (the path shows on screen). Open it and compare "Design Capacity" with "Full Charge Capacity". If the current capacity is much lower than the original, the battery is spent.
On Mac: Apple menu > System Settings > Battery > Battery Health. If it says "Service Recommended", it's time.
Internal or removable battery?
Older laptops have a battery that pops out from outside with latches — swapped in seconds, no tools. Newer ones have an internal, screwed-in battery, so you open the bottom cover. Not sure which you have? Tell us the model.
Replacing an internal battery — step by step
- Shut the laptop down and unplug the charger.
- Discharge static by touching a metal surface before opening.
- Open the bottom cover with a small screwdriver. Some screws hide under the rubber feet.
- Find the battery and gently unplug its connector from the board — pull the connector, never the wires.
- Remove the battery screws and lift it out.
- Fit the new battery, screw it down, plug the connector back in and close the cover.
- Charge to 100%, run it down, then charge once more to calibrate.
Important: never puncture or bend a swollen battery. If it's swollen, bring it in — we handle it safely.
Which battery to buy for your model
The right battery depends on the exact model. Flip the laptop over and read the label underneath, or the number printed on the battery itself. We stock new batteries for the brands we see most:
- HP laptop batteries
- Asus laptop batteries
- Lenovo laptop batteries
- Acer laptop batteries
- Dell laptop batteries
- MacBook batteries
Can't find your model? Send us the part number and we'll confirm it.
Rather we did it for you?
We do this work every day at our shop in Entrecampos (Rua de Entrecampos 34A, Lisbon — right by the Entrecampos metro and train station). Over 8,000 devices repaired since 2023 and 4.9★ on Google.
New parts come with a 3-year legal guarantee (Portuguese law DL 84/2021). Tell us the model and we'll give you the price on the spot.